Azamat Tazhayakov, 20, is accused of removing items from Tsarnaev’s dorm room at the University of Massachusetts-Dartmouth several days after last year’s deadly attack.

Jury selection began Monday with 225 potential jurors brought into the federal courthouse and asked to fill out questionnaires.

Another large group will be brought in Tuesday.

Judge Douglas Woodlock said 12 regular jurors and six alternates will be chosen.

Three people were killed and more than 260 were injured when two pressure cooker bombs exploded near the marathon’s finish line.

Prosecutors say Tazhayakov and another friend, Dias Kadyrbayev, took Tsarnaev’s backpack containing fireworks after seeing Tsarnaev’s photograph on the news and realizing he was a suspect. The items were later recovered in a landfill.

Kadyrbayev faces a separate trial in September.

Tazhayakov is not charged with having anything to do with the bombings. His lawyer has said he expects him to testify in his own defense.

Opening statements are scheduled for July 7.

The judge said he expects the trial to last about three weeks.

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